1. Field of Invention
The present invention relates to, in general, a parallel double clutch device for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission and, in particular, a drivetrain having the parallel double clutch device.
2. Description of Related Art
U.S. Pat. No. 7,246,692 B2 describes a parallel double clutch device having a first clutch arrangement and having a second clutch arrangement which are arranged in an axially staggered fashion, with the first clutch arrangement serving for the selective transmission of torque between a drive unit and a first transmission input shaft, while the second clutch arrangement serves for the selective transmission of torque between the drive unit and a second transmission input shaft. The two clutch arrangements can be actuated in each case by a hydraulically drivable actuating piston. For this purpose, each of the two actuating pistons is assigned a pressure chamber which is delimited by a pressure chamber housing and the respective actuating piston. The pressure chamber housing is formed in each case by a section of an inner rotating input hub of the parallel double clutch device. Furthermore, a compensating chamber for centrifugal oil compensation is provided on that side of each actuating piston which faces away from the pressure chamber. The abovementioned input hub of the parallel double clutch device is of substantially tubular design, with the tubular input hub being supported in the radial direction on a stationary support tube. To act on the pressure chambers with pressurized oil and thereby be able to drive the actuating piston, rotary leadthroughs are provided between the clutch input hub and the support tube, which rotary leadthroughs are separated from one another by corresponding rotary leadthrough seals.
The known parallel double clutch device has proven itself but is afflicted with some disadvantages. Firstly, the hydraulic system for driving the actuating piston is subject to leaks, such that the use of a high-pressure accumulator for increasing the efficiency of the parallel double clutch arrangement is duly possible but leads to increased leakage losses. Secondly, the known parallel double clutch device has a complex design which takes up a large amount of installation space.
It is therefore an object of the present invention to provide a parallel double clutch arrangement which firstly ensures substantially leak-free operation even at high pressure of the hydraulic medium and if appropriate with the use of a high-pressure accumulator, and which secondly has a simple and installation-space-saving design. The present invention is also based on the object of providing a drivetrain having a parallel double clutch device with such advantages.